Photochemical Energy Conversion with Artificial Molecular Machines

Abstract

The exploitation of sunlight as a clean, renewable, and distributed energy source is key to facing the energetic demand of modern society in a sustainable and affordable fashion. In the past few decades, chemists have learned to make molecular machines, that is, synthetic chemical systems in which energy inputs cause controlled movements of molecular components that could be used to perform a task. A variety of artificial molecular machines operated by light have been constructed by implementing photochemical processes within appropriately designed (supra)molecular assemblies. These studies could open up new routes for the realization of nanostructured devices and materials capable to harness, convert, and store light energy.

2021 Pioneers in Energy Research: Vivian Yam

“…Leung and Lau 25 summarize the photophysical properties of organic dyes and recent applications in photocatalytic reduction of water and carbon dioxide. Credi and co-workers 26 provide the state-ofthe-art light-driven artificial molecular machines via implementing photochemical processes within well-designed (supra)molecular assemblies. Wu and co-workers 27 report a high-efficiency H 2 evolution photosystem based on S 2−stabilized CdS (CdS−S 2− ) quantum dots (QDs) and watersoluble Ni 2+ salts (pH 6.0), in which the Ni 0 clusters formed in situ bind to the surface of QDs via a Ni−S bond to work as the real catalytic species for H 2 photogeneration.…”

Interface Asymmetry Induced and Surface Pressure Controlled Valence Tautomerism in Monolayers of bis-Phthalocyaninates of Lanthanides

“…The design of "smart" materials based on molecular switches seems to be a promising step towards the miniaturization of electronics components and the creation of new functional materials. At present, under the impact of the miniaturization idea, new types of molecular devices are being actively studied and elaborated [1][2][3][4][5][6]. From these standpoints, supramolecular systems based on transition metal complexes with redox-active ligands, which are capable of reversible redox-isomer switching due to intramolecular electron transfer, become one of the most interesting objects [7][8][9].…”

“…Symmetry 2022, 14, 340 2 of 14 of molecular devices are being actively studied and elaborated [1][2][3][4][5][6]. From these standpoints, supramolecular systems based on transition metal complexes with redox-active ligands, which are capable of reversible redox-isomer switching due to intramolecular electron transfer, become one of the most interesting objects [7][8][9].…”

Autonomous Non-Equilibrium Self-Assembly and Molecular Movements Powered by Electrical Energy

“…1 For this reason, scientists have attempted to create artificial systems that display autonomous behavior, i.e., operate under constant environmental conditions, harnessing energy from the surrounding environment. 2,3,4,5,6,7,8 The minimal form of autonomous chemical system is composed by a cyclic sequence of reactions that occurs spontaneously. In such a non-equilibrium system, energy needs to be supplied to impart a directionality in the reaction network, leading to the emergence of a chemical current (Figure 1a).…”